1. To power on, press and hold the Screen Lock/Power key.
   
2. Press and hold again to power the device off.
   
3. If you are unable to turn your phone on, plug the phone into a power source, and then try again.
   
4. If you are unable to turn your phone off with the Power key, remove and re-insert the battery.
   Note: See 'Phone assembly' for details.